What Elements makes up a Packet Radio Station
TNC (terminal Node Controller)
- A TNC contains a modem, a computer processor (CPU), and the associated circuitry required to convert communications between your computer (RS-232) and the packet radio protocol in use. A TNC assembles a packet from data received from the computer, computes an error check (CRC) for the packet, modulates it into audio frequencies, and puts out appropriate signals to transmit the packet over the connected radio. It also reverses the process, translating the audio that the connected radio receives into a byte stream that is then sent to the computer. Common speed is 9600 bps, higher speeds are available for use in the UHF, and especially microwave region, but they often require special (not plug-and-play) hardware and drivers. HF Data communication is available for reasonable costs at speeds that do not go over 1200 bps